Dividing mixed
numbers is very similar to multiplying mixed numbers. You just add one stepafter
changing the divisor into an improper fraction, you then find its reciprocal
and multiply. Let's work through a "word problem" example.

The SuperQuik
Market has just installed new scanners for its check-out lanes. They claim
the average time to check out a customer is 2 ½ minutes. How many customers,
on average, can they check out in half an hour?

To solve this
problem, we have to know that half an hour is the same as 30 minutes. Then
we can divide 30 by 2 ½.

First step:
Write the whole number and the mixed number as improper fractions.

Second step:
Write the reciprocal of the divisor, 2/5, and multiply.

Third step:
Simplify, if possible. Notice that we can simplify our problem at this step,
to make our calculations easier. Five goes evenly into 30, so we can divide
both 5 and 30 by 5, to give 1 and 6.

Fourth step:
Perform the simple multiplication of the numerators and the denominators.
We find that the market can check out 12 customers in 30 minutes with its
new scanners.

Fifth step:
Put the answer in lowest terms, and check the answer. Our answer is already
in lowest terms, so there is nothing left to do but check the answer, to be
sure it makes sense. We can use estimation and rounding to do our check. If
we round 2 ½ minutes to 3 minutes and divide 3 into 30, we get 10 customers
in 30 minutes. So it is reasonable that 2 more customers per half hour, or
12 customers, can be checked, since 2 ½ minutes per customer is less
than 3 minutes per customer.